1. Field of the Invention
The present invention relates to a semiconductor structure combination and, more particularly, to a semiconductor structure combination for a semiconductor optoelectronic device.
2. Description of the Prior Art
The current semiconductor light-emitting devices, such as light-emitting diodes, have been used for a wide variety of applications, e.g. illumination, remote control. To ensure high functional reliability as great as possible and a low power requirement of the semiconductor light-emitting devices, the external quantum efficiency is required for the devices.
In theory, the external quantum efficiency of a semiconductor light-emitting device is determined by the internal quantum efficiency thereof. The internal quantum efficiency is determined by the material property and quality. If a density of inner defects of the semiconductor light-emitting device becomes higher, it will lower the internal quantum efficiency and light-extraction efficiency of the semiconductor light-emitting device.
To enhance the external quantum efficiency of the semiconductor light-emitting device, a sapphire substrate with a patterned surface has been disclosed and applied to the manufacture of the semiconductor light-emitting device. The patterned surface is for scattering light emitted out from the semiconductor light-emitting device to reduce the probability of a total reflection, and further enhancing the external quantum efficiency of the semiconductor light-emitting device.
Although a semiconductor material layer, e.g. GaN, can be formed on the patterned surface of the sapphire substrate by a good lateral epitaxy, many inner defects, e.g. formed-through dislocations, are still generated after the epitaxy of the semiconductor material layer on the patterned surface of the sapphire substrate and affect the optoelectronic performance of the semiconductor light-emitting device directly. Therefore, the quality of the semiconductor material layer formed on the patterned surface of the sapphire substrate is still required of improvement.
Therefore, the main scope of the invention is to provide a semiconductor structure combination for a semiconductor optoelectronic device to solve the above problems.